when exporting RTF from Indesign CS6 some images are missing. All Images (those OK as well as those missing) are placed in anchored frames. In the Links view I checked that all references are resolved. They are not marked not to print.

Any ideas what I should look for? I must add that I am a rather basic Indesign user. Searching the forum I found a few similar questions, but no answers yet.

I can't find it right now, but there was another thread about this sometime in the last six to twelve months. I suspect that it has something to do with the RTF-writing abilities of InDesign. My recollection was that the image data was actually in the RTF, but it was not being rendered.

What are you using to view your RTFs? Can you look at the RTFs in another application (LibreOffice, TextEdit, et cetera) to verify that it's an RTF-source problem and not an RTF-viewer problem? I deal with quite a few applications that write, ah, flaky RTFs (many translation tools do this poorly) and sometimes you can fix flaky RTFs by simply opening up the RTF in another application, making an insignificant change, and resaving.

Another thing to look for is the formats of the placed images - you say some are missing. But are all the missing images (or all the present images) saved in a single format?